Hippocampal subfield size predicts the precision of memory recall

11 July 2014

The hippocampus is a brain structure crucial for forming and
recollecting memories of our personal experiences, which are known as episodic
memories. It was thought that each memory is processed by a completely separate
set of neurons within a part of the hippocampus called CA3.

However, using
functional MRI brain scanning, researchers atUCL Institute of Neurology funded
by the Wellcome Trust, have found that CA3 "memory traces" can
in fact overlap when the memories are very similar to one another, leading to
the experience of memory confusion or interference.

Intriguingly, the
researchers also found that variations in the physical size of CA3 predicted
differences in the extent of memory trace overlap and memory confusion across
the research participants.

A larger CA3 may contain more neurons or more connections between neurons, which could allow greater physical separation of the different memory traces.

Dr Martin Chadwick, Lead Author

Our results may help to explain why we sometimes find it difficult to differentiate between similar past memories, and why some people are better at doing this than others.